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A "nest" of Bird scooters on Cowperthwaite Street in Cambridge (Robin Lubbock/WBUR)

For the first time, researchers have been able to assess how dangerous electric scooters are.

Electric scooters — from companies such as Bird, Skip and Lime — have become a popular transportation alternative and can be found in many cities across the country. But a new report in JAMA Network Open puts the scooters' previously foggy public health impact into perspective.

Researchers at UCLA have found that 1 in 3 people in the Santa Monica, California, area involved in an electric scooter accident were hurt so severely, they needed to be transported to an emergency room by ambulance.

"The injuries did vary in severity but some of them were so severe that the patients had to be hospitalized," Dr. Joann Elmore (@JoannElmoreMD), senior author of the study and director of the UCLA National Clinician Scholars Program, tells Here & Now's Lisa Mullins.

The most common injuries researchers saw were fractures, according to Elmore. Most injuries resulted from falls, collisions or being struck by a moving vehicle or object.

The study found less than 5 percent of the patients wore helmets while riding, signaling a low rider adherence to the safety protocols — such as wearing a helmet — that e-scooter companies recommend.

"We need to encourage riders to be careful," Elmore says. "They need to follow local traffic laws and they need to wear helmets to prevent the type of injuries that we've seen in our emergency departments."

Interview Highlights

On the most common injuries resulted from e-scooter accidents

"The most common injuries are probably fractures, but we had about 40 percent of the patients with head injuries. ... The two patients that required intensive care unit, one of them had what's called a traumatic subarachnoid hemorrhage and the other one had a subdural hematoma. Basically, when you fall and hit your head with such force, there can be bleeding."

On the cause of most electric scooter-related injuries

"What we noticed is that these individuals were either falling off of the scooters — that's the majority of them from what we could tell — or they were hitting moving objects. In fact, we were surprised, I had assumed that all of the injuries that were seeing in our two emergency departments would be from riders, but we actually had 8 percent of the patients who were nonriders. They were either walking along and they tripped over the scooters that were left in a sidewalk, or someone on a scooter hit them."

On what e-scooter riders can do to prevent hurting themselves

"We have data from motorcycles and from bicycles in which wearing helmets can help to reduce the traumatic brain injury. So I really do think it could be helpful."